This application claims priority from United Kingdom Patent Office Application No. 9926241.2, filed Nov. 6, 1999.
1. Technical Field
The present invention relates to cable clamps for securing cables in data processing equipment and more particularly to cable clamps for securing a plurality of cables without the use of screws or tools.
2. Background Art
Conventionally clamps used to secure cables are xe2x80x9cPxe2x80x9d style clips, with a separate clip being required to secure each cable. Each cable is clamped individually using a separate clip and screw. Such xe2x80x9cPxe2x80x9d style clips need a driver, such as a screwdriver or a nutdriver, to be used in order that the cable be removed. This type of clamp has proved to be time consuming and costly to use and has resulted in poor control of the pressure being applied to the cables. The use of screws can result in too much pressure being applied on the wires which causes the insulation to split or break open and shorts to occur. Computer servers frequently have many cables exiting the computer enclosure and each of the cables must be clamped at the rear of the server. It has became evident that a strain relief device was required which was economical, simple to assemble, and which could be easily used without uncontrolled pressure being applied to the wires.
Accordingly, the present invention provides a strain relief for a plurality of cables, the strain relief comprising: a first portion having a first surface having a plurality of first hook elements projecting from the first surface, each hook element being for retention of one of the plurality of cables, the first surface having a plurality of second hook elements projecting from the first surface, each second hook element being for retention of said one of the cables; and a second portion having a cable receiving opening corresponding to the cable receiving opening in the first portion, the second portion latching to the first portion, so as to clamp the plurality of cables.
The use of a second closing portion having cable receiving openings, make the strain relief easy to use as no tools are required and the usage is intuitive. The elimination of the use of clamping screws used in the prior art allows for better control of the clamping pressure on the wires by the assembly. Simple snapping of the portions together with no adjustment required prevents ineffective clamping of the wires too loosely or clamping of the wires too tightly which would cause crushing of the wires and breaking of the insulation resulting in short circuits.
Preferably, each of the first hook elements are oriented in a first direction, each of the second hook elements are oriented in a second direction, the second direction being opposed to the first direction.
The use of oppositely directed hook elements improves the strength of the strain relief.
The hook elements are so formed so that they, not the snap on cover, resist any vertical pull force applied to the cable. This has the advantage that the cover and its latch do not have to be solidly constructed making them cheaper to make and easier to use.
Preferably, the strain relief further comprises a plurality of third and a plurality of fourth elements, projecting from the first surface, each of the third and fourth elements being located between the plurality of first hook elements and the plurality of second hook elements, each of the third and fourth elements having a cable receiving opening corresponding to each of the cable receiving openings in each of the first and second hook elements of the first portion.
Further preferably, the second portion of the strain relief is hingeably attached to the first portion at a first end of the first surface and, in use, is latchedly attached to the end of the first surface distal from the first end.
The second portion being a captive part has the advantage that it cannot be mislaid.